MURRIETA (CBSLA.com) — New details have been released about two teenagers who are accused of plotting a mass homicide on a Murrieta high school campus.

15-year-olds Reed Peery and Samuel Noble were arrested Aug. 16 on charges of conspiracy to commit murder at Vista Murrieta High School, according to investigators.

Police and the Federal Bureau of Investigation traced threats that were allegedly made over the internet to an IP address linked to the suspects.

A police report, which was obtained by the Murrieta Patch, said: “During the conversation over the Internet, the subject(s) explained a plan to use napalm and C-4 explosives while shooting people…”

“(Peery) determined they would use pipe bombs and Molotov cocktails to aggress each individual classroom, setting fire to the classrooms and shooting any students who fled from the classroom,” according to the report.

Police said Peery’s mother consented to a search and handed over her son’s computer and cell phone.

The attack was allegedly planned for April 20, 2015—the anniversary of Adolf Hitler’s birthday and the Columbine shootings in Colorado.

The Murrieta Valley Unified School District said it can’t legally comment on the case.